It is a racial taunt made by the president of the United States, not unlike his discredited claim that Barack Obama was not born in America.

And just as President Trump’s embrace of birtherism led to the remarkable spectacle of President Obama’s birth certificate being distributed in the White House, Mr. Trump’s unrelenting mockery of Senator Elizabeth Warren as “Pocahontas” — questioning her claims about having Native American heritage — has prompted Ms. Warren to release the results of a DNA test that she says provide proof of her ancestry.

There is “strong evidence” that Ms. Warren has Native American pedigree “6-10 generations ago,” according to a document she released Monday from Dr. Carlos Bustamante, a renowned geneticist. The error rate is less than one-in-a-thousand, he said.

Democratic Senator Elizabeth Warren, ridiculed by U.S. President Donald Trump as “Pocahontas” for claiming Native American heritage, hit back on Monday with DNA evidence she said supported her assertion, a possible preview of a bare-knuckles presidential campaign in 2020.

The Massachusetts lawmaker, known as a liberal firebrand in her party, said last month she would take a “hard look” at running for the Democratic nomination to challenge Republican Trump in 2020. She and Trump clashed frequently through the 2016 presidential campaign and Trump has cast aspersions on her claim to Native American ancestry.

“When I decided to run for Senate in 2012, I never thought that my family’s Native American heritage would come under attack and my dead parents would be called liars,” she said in a statement on Monday.

The Cherokee Nation called Sen. Elizabeth Warren’s DNA test to prove her Native American ancestry “inappropriate and wrong” in a statement Monday.

“Sovereign tribal nations set their own legal requirements for citizenship, and while DNA tests can be used to determine lineage, such as paternity to an individual, it is not evidence for tribal affiliation,” the Cherokee Nation’s Secretary of State Chuck Hoskin Jr. said. “Using a DNA test to lay claim to any connection to the Cherokee Nation or any tribal nation, even vaguely, is inappropriate and wrong.”

Earlier Monday, Warren published a DNA test to show that she has some Native American ancestry. This was in response to frequent allegations by President Trump that she used false claims of her heritage to advance her career. Trump has repeatedly disparaged Warren by referring to her as “Pocahontas.”